A Ginzburg-Landau theory for Ni-Mn-Ga

We present an effective Ginzburg-Landau theory for ferromagnetic cubic Ni-Mn-Ga in which structural and magnetic phase transitions take place. The general problem of a cubic ferromagnet is taken into account by fitting the parameters of the Ginzburg-Landau functional to experimental data. This enables us to obtain a realistic phase diagram for Ni-Mn-Ga.